what grease to use

Probably the one specified in the 2nd manual you linked to. "All friction points on the wheel brake must be lubricated with Molybdenum Disulphide Grease"

:-)

Yes I would say that should be good

A moly grease sounds good to me for the brake bits, and that's what AlCo say too.

Although Copaslip seems to be made by Molyslip, it doesn't contain moly disulphide (but does contain copper).

What worries me very slightly about the Castrol offering is that being a lithium grease it won't be quite so water resistant as, for example, the Renolit Aqua 2 which is a calcium grease (but doesn't contain moly).

Lithium grease is commonly used in wheel bearings because of its high melting point, I wouldn't expect the auto reverse to need heat resistance.

You won't need much moly grease, in your position I would probably try to get the AlCo stuff for the adjusters and sliding bits in the auto reverse. But I wouldn't agonise too much if you can't find it, there are plenty of moly options on Google, eBay, and car accessory shops (note though that most of them seem to be Lithium).

This one looks to have a high moly disulphide content

I also use moly grease on ball hitches and their levers and latches.

It would be a bad thing if the grease melted all over the brake shoes. The hubs may get quite warm under braking.

Andy

True, it does depend on the details of the mechanism and I will confess to not looking closely at the diagrams, but when I had a horse trailer one part of the anti-reverse system was away from the hubs, with a link (I think).

The reason copaslip is used between brake pads and calipers is that these places can get very hot, and copaslip is essentially non-melting. "Dry" moly disulphide sprays can be used in these places. (They are used on things like kiln trolley chains for the same reason).